a huge head, square jaw with
heavy side whiskers, and eyes that moved restlessly under a shock of
iron-gray hair. Whether it was the actual size of his head or his bushy
hair, one got the impression that his cranium housed a superabundant
supply of brains.

Every action was nervous and quick. Even his speech was rapid, as though
his ideas outstripped his tongue. He impressed one as absorbed in this
thing which he said frankly had been his life study, every nerve
strained to make it succeed and convince people.

"Just what is this force you call vibrodyne?" asked Craig, gazing about
at the curious litter of paraphernalia in the shop.

"Of course, I'm willing to admit," began Creighton quickly, in the tone
of a man who was used to showing his machine to skeptical strangers but
must be allowed to explain it in his own way, "that never before by any
mechanical, electrical, thermal, or other means has a self-moving motor
been made."

He paused apparently to let us grasp the significance of what he was
about to say. "But, is it impossible, as some of the old scientists have
proved to their own satisfaction it must be?" he went on, warming up to
his subject. "May there not be molecular, atomic, even ionic forces of
which we have not dreamed? You have only to go back a few years and
study radioactivity, for instance, to see how ideas may change.

"Today," he added emphatically, "the conservation of energy, in the old
sense at least, has been overthrown. Gentlemen, all the old laws must
be modified by my discovery of vibrodyne. I loose new new forces--I
create energy!"

I watched him narrowly as he proposed and rapidly answered his own
questions. He was talking quite as much for Miss Laidlaw's benefit, I
thought, as ours. In fact, it was evident that her interest in the
machine and in himself pleased him greatly.

I knew already that though the search after perpetual motion through
centuries had brought failure, still it captivated a certain type of
inventive mind. I knew also that, just as the exact squaring of the
circle and the transmutation of metals brought out some great
mathematical discoveries and much of modern chemistry, so perpetual
motion had brought out the greatest of all generalizations of
physics--the conservation of energy.

Yet here was a man who questioned the infallibility of that
generalization. Actually taking the ultra-modern view that matter is a
form of energy, he was asserting that energy in